Swallowtail Butterfly

=== Subfamilies === The genera of extant swallowtails are usually classified into three subfamilies, Baroniinae, Parnassiinae, and Papilioninae, the latter two being further divided into tribes. In swallowtails, besides morphological characteristics, the choice of food plants and ecological lifestyle reflect phylogeny and classification.

The Baroniinae are a monotypic subfamily, restricted to a very small region in Mexico and are considered to be the most basal of the subfamilies. Baronia brevicornis is considered to be a relict species, and shares features with a fossil taxon Praepapilio. Baronia is unique among papilionidae' as having an Acacia species (family Leguminosae) as its food plant. Subfamily: Baroniene. Baronia brevicornis.jpg|

The Parnassiinae are a subfamily of essentially Holarctic butterflies. The vast majority of species, mostly Parnassius, can be found in mountain habitats. Parnassiinines can also be found in other habitats such as "arid deserts (Hypermnestra), humid forests (Luehdorfia) and even lowland meadows (Zerynthia)". The tribes recognized in the Parnassiinae are Parnassiini, Zerynthiini, and Luehdorfiini. Tribe Parnassiini contains two genera, Hypermnestra, largely confined to central Asia and the genus Parnassius (the Apollos), a distinctive group of many species, all of which are alpine and capable of living at high altitudes. Most Parnassius have two small reddish spots on their hindwings. The tribe Luehdorfiini contains the genera Archon of Asia minor and the genus Luehdorfia of China and Japan. These two tribes have evolved to change their food plants, while the third tribe, Zerynthiini, has retained the archetypical papilionid food plant, the lowland vine Aristolochia. Zerynthiini comprises four genera – Sericinus, Bhutanitis, Zerynthia and Allancastria. Subfamily: Parnassiinae. Apollo butterfly.JPG| Archon_apollinus_bellargus_1.jpg| Spanish festoon (Zerynthia rumina).jpg| BhutliddCRW_4351.jpg|

The tribes recognized in the Papilioninae are Leptocircini, Teinopalpini, Troidini, and Papilionini. Subfamily: Papilioninae. Zebra Swallowtail Megan McCarty10.jpg| Teinopalpus imperialis verso.JPG| Trogonoptera trojana male 5.jpg| Papilio troilus01.jpg| Old World swallowtail (Papilio machaon gorganus) underside Italy.jpg| Cairns birdwing - melbourne zoo.jpg| Western Tiger Swallowtail (Papilio Rutulus).jpg| Voutyro 2017 822 zoom.jpg|

An additional subfamily, Praepapilioninae, consisting of a single genus Praepapilio, includes two species of extinct butterflies, each member being described from single fossils found in a middle Eocene deposit in Colorado, United States (Durden and Rose, 1978).

A phylogeny of the Papilionidae based on Nazari (2007) is given: The Parnassinae, like the Papilioninae, were also believed to be monophyletic based on morphological studies but recent studies based on both morphological and molecular characteristics suggest that this is not the case. and are now considered to be part of the tribe Parnassiini. The two taxa, Archon and Luehdorfia, have been found to be closely related through analysis of nuclear and mitochondrial DNA, and, though they share no morphological similarities, have now been united in the tribe Luehdorfiini. The subfamily Baroniinae is represented by the sole representative species Baronia brevicornis. They are unique in the family to use the Fabaceae (Leguminosae) as their larval host plants. The Baronninae and the extinct subfamily Praepapilioninae share many external similarities and are traditionally considered to be the most primitive subfamilies and sister to the rest of the swallowtails. Recent research suggests that this may not be the case, the Baroniinae being closely related to only the Parnassiinae, and Praepapilio to only the Papilionini and neither taxa being sister to the rest of the swallowtails.

As of 2005, 552 extant species have been identified which are distributed across the tropical and temperate regions. Various species inhabit altitudes ranging from sea level to high mountains; species of Parnassius in particular often live at higher elevations. The majority of swallowtail species and the greatest diversity are found in the tropics and subtropical regions between 20°N and 20°S, particularly Southeast Asia, and between 20°N and 40°N in East Asia. Only 12 species are found in Europe and only one species, Papilio machaon, is found in the British Isles. North America has 40 species, including several tropical species and Parnassius. The northernmost swallowtail is the Siberian Apollo (Parnassius arcticus), north of the Arctic Circle in northeastern Yakutia, at altitudes of 1500 meters above sea level. In the Himalayas, various Apollo species such as Parnassius epaphus have been found at 6,000 meters above sea level.

, lavender, near Adriatic|alt=Scarce swallowtail (Iphiclides podalirius) on lavender flowers, near the Adriatic]] The caterpillars of various swallowtail butterfly species feed on a wide range of different plants, most depending on only one of five families: Aristolochiaceae, Annonaceae, Lauraceae, Umbelliferae (Apiaceae) and Rutaceae. By eating some of these toxic plants, the caterpillars sequester aristolochic acid which renders both the caterpillars and the butterflies of some of these as toxic, thus protecting them from predators. Similarly, the Parnassius smintheus sequesters sarmentosin from its host plant Sedum lanceolatum for protection from predators. Swallowtail tribes Zerynthiini (Parnassiinae), Luehdorfiini (Parnassiinae) and Troidini (Papilioninae), almost exclusively use the family Aristolochiaceae as their host plants. For example, the eastern black swallowtail's (Papilio polyxenes) main host plant in the wild is Queen Anne's lace, but they also eat garden plants in the carrot family, including carrots, parsley, dill, and fennel. Adult swallowtails sip nectar, but also mud and sometimes manure.

The detailed descriptions of morphological characteristics of the Papilionidae, as quoted in Bingham (1905) are as follows: Stages of development of a papilionid, the giant swallowtail (Papilio cresphontes) Giant Swallowtail Egg.jpg|Egg Giant Swallowtail Larva.jpg|Larva Papilio cresphontes chrysalis.JPG|Pupa Butterfly 8731-2.jpg|Butterfly

The key characteristics that differentiate the Papilionidae from the other butterfly families are: * The osmeterium is a forked, fleshy eversible organ found in the prothoracic segment of caterpillars. * Venation – in swallowtails, the second anal vein, 2A, extends up to the wing margin and does not link with the first anal vein, 1A. These veins are fused in other butterfly families and 2A does not reach the wing margin. * The sclerites of the cervix (membranous neck between the head and thorax) are fused beneath the neck where the muscles for head movement are anchored. 01 chenille machaon (detail).jpg|Old World swallowtail caterpillar everting its osmeterium in defense. Papilio demodocus larva IMG_8543s.jpg|Papilio demodocus larva applying one horn of the evaginated osmeterium to an offending finger. Papilionidae id char venation.png|Adult forewing of Graphium agetes. Second anal vein, 2A, extends up to the wing margin and does not link with the first anal vein, 1A. Black Swallowtail Chrysalis Megan McCarty33.jpg|Papilionid chrysalis are typically attached to a substrate by the cremaster and with head up held by a silk girdle.

Swallowtail butterflies practice Batesian mimicry, a behavior in which the butterflies' appearance closely resemble that of distasteful species that prevents predation. Swallowtails differ from many animals that practice mimicry. The tiger swallowtail butterfly (Papilio glaucus), exhibits a female-limited polymorphism for Batesian mimicry and others, such as the Canadian tiger swallowtail (Papilio canadensis) do not display any form of mimicry. Predators include the red-winged blackbird, Pennsylvania firefly, five-lined skink, green darner, goldenrod spider, Chinese mantis, fiery searcher, and striped skunk.

Not all individuals in some species are identical in appearance. For example, Papilio glaucus (eastern tiger swallowtail), Y-linkage determines whether the females are either wild-type (yellow and black) or melanic (dark melanin replaces the yellow background). This genetic difference stems from the fact that melanism is controlled by a single gene, which controls the level of dopamine in the organism. The enzyme BAS, which assists dopamine in producing the yellow pigmentation, normally found on the wings' background, is suppressed. Without the pigmentation, the butterfly appears mostly black (the melanic form) and is a Batesian mimic of Battus philenor, the pipevine swallowtail. There are also Papilio glaucus that are not wholly black; several possess an intermediate "sooty" color and are sensitive to temperature. The different polymorphisms (wild-type, melanic, and the 'sooty' intermediate) depend upon the geographical distribution and abundance of its mimic, the Battus philenor, whose wing color varies depending on its geographical location. In order to be successfully confused for the B. philenor by predators, the Papilio glaucus's background wing color matches that of the B. philenor residing in the same regional area. Studies support this theory; in the southeastern United States, the relative abundance of melanic females has been found to geographically correlate with B. philenor.

Only certain subsets of swallowtails practice mimicry. Species differ in whether one or both sexes is mimetic, and whether the mimicry is monomorphic or polymorphic. A phenomenon which has received particular attention is female-limited polymorphism, in which only the females of a species are mimetic and polymorphic, often mimicking different, distantly-related aposematic butterflies. This polymorphism is seen in Papilio dardanus, the African swallowtail butterfly, whose females have three different morphs for wing color pattern: a black-and-white pattern for Batesian mimicry, a black-and-yellow pattern that resembles the males of the species, and a pattern with orange patches that resembles the elderly males of the species. Given that the males of the species, which do not have Batesian mimicry, are preyed upon much more frequently by predators than the females, an ongoing question is why females would exhibit the non-mimetic wing pattern, which would seemingly lower their fitness compared to the mimicry form. The pipevine swallowtail exhibits Batesian mimicry as well. Several hypotheses for this phenomenon were made, the two noteworthy being the pseudosexual selection hypothesis and the male avoidance hypothesis. In the pseudosexual hypothesis, male butterflies aggressively approached the male-looking females and then mellowed their behavior into sexual behavior when they were close enough to identify them as females. In the male avoidance hypothesis, female butterflies disguise themselves in an attempt to evade male harassment, as courtship can be harmful, time-consuming, and attract predators. One study recorded male responses to females of each morphs and found that the males consistently favored the Batesian mimics, then the black and yellow, and then the morph with orange patches. The scientists concluded that frequency-dependent selection did lead to equal success for all three alternative strategies: the Batesian females suffered the fewest predators but their fitness was reduced the most by sexual harassment, while the other two faced lower sexual harassment but also lost fitness from predators' attacks.

After mating, the male Parnassines produce a glue-like substance that is used to seal the female genital opening and prevent other males from mating. They lay individual eggs on the underside of the leaves of their food plants. There is no parental investment once the eggs have been laid. The pupae are typically attached to the substrate by the cremaster but with head up held by a silk girdle. The Apollos, however, pupate in debris on the ground and also build a loose cocoon. In the temperate regions, the winters are passed in a pupal diapause stage.

Since swallowtail butterflies are large, colorful, and attractive, they have been targeted by butterfly collectors. The largest of these, the birdwing butterflies are particularly sought after and are cultured in butterfly farms to supply collectors. Many members of the family, as larvae, feed on plants of the citrus family Rutaceae, and some of them are pests in citrus orchards. The Oregon swallowtail is the state insect of Oregon. The eastern tiger swallowtail is the state insect of Virginia and the state butterfly of Georgia, Delaware, and South Carolina. The black swallowtail is the state butterfly of New Jersey and Oklahoma. The tabletop role-playing game Lancer includes a support- and sensor-focused mech named the Swallowtail.